The present invention is generally directed to conserving power in a telecommunications network. More specifically, the present invention is directed to conserving power in a wireless telecommunications network in emergency situations.
In a wireless telecommunications network, telephone calls can be initiated by users activating a wireless communication device (e.g., cellular telephone, personal digital assistant, laptop computer, etc.). The wireless communication device is recognized by a base station in the wireless telecommunications network, and the base station gives authorization to the wireless communications device to make a call. A user typically inputs (i.e., dials) digits using a wireless communication device, and the wireless communication device transmits the digits to the base station. The base station typically relays the incoming digits to a Mobile Switching Center (MSC), which processes the digits and routes the call to a destination associated with the dialed digits.
Base stations and MSCs consume power when processing and routing calls. Usually, commercial power is supplied from an electric utility. In this case, as much power as needed in order to set-up, connect, and disconnect calls is typically supplied to the base stations and MSCs from the electric utility. However, in the event of a power blackout, no commercial power is available to wired and wireless switching networks. In this case, electricity generators are typically used at telephone central offices to provide backup power. Also, battery back-up is typically available at base stations and smaller switching locations to provide power. The amount of time the back-up power supplied by generators and batteries lasts is limited and depends on the calling load and the demand placed on the switching systems.
During emergency situations which can lead to power outages, such as natural disasters or terrorist attacks, many users typically attempt to call public based emergency services, such as 911, to alert police, fire, and medical personnel. Furthermore, some government and business officials can place priority calls using Government Emergency Telecommunications Service (GETS) or Wireless Priority Service (WPS), such that their calls are prioritized over other calls. These services can be utilized by a user entering a special code along with a telephone number. Also, during emergency situations, mass calling from the population can occur, which causes congestion of telecommunications networks. Thus, during emergency situations, the call load in a telecommunications network and the demand on switching systems is typically higher than normal. Accordingly, back-up power supplies are depleted rapidly during emergency situations, when emergency calling and priority calling are at their peak need.